U.S. Pat. No. 5,848,582 discloses a control system for a fuel injector system for an internal combustion engine that is provided with a method by which the magnitude of the start of air point for the injector system is modified according to the barometric pressure measured in a region surrounding the engine. This offset, or modification, of the start of air point adjusts the timing of the fuel injector system to suit different altitudes at which the engine may be operating.
U.S. Pat. No. 5,924,404 discloses a direct fuel injected two-stroke engine that controls spark ignition timing and/or ignition coil dwell time on a cylinder-specific basis. The engine also preferably controls fuel injection timing and amount and injection/delivery duration on a cylinder-specific basis. Cylinder-specific customization of spark ignition and fuel injection allows better coordination of spark with fuel injection which results in better running quality, lower emissions, etc. Memory in the electronic control unit for the engine preferably includes a high resolution global look-up table that determines global values for spark ignition and fuel injection control based on engine load (e.g. operator torque demand, throttle position, manifold air pressure, etc.) and engine speed. Memory in the electronic control unit also includes a plurality of low resolution, cylinder-specific offset value look-up tables from which cylinder-specific offset values for spark ignition and fuel injection can be determined, preferably depending on engine load and engine speed. The offset values are combined with the global values to generate cylinder-specific control signals for spark ignition and fuel injection.
U.S. Pat. No. 5,988,139 discloses an engine control system that digitally stores corresponding values of timing angles and engine speeds and selects the timing angles based on the operating speed of the engine. In the engine speed range near idle speed, the timing angle is set to a pre-selected angle after top dead center (ATDC) and the relationship between engine speed and timing angle calls for the timing angle to be advanced from the pre-selected angle after top dead center (ATDC) to successively advancing angles which subsequently increase angles before top dead center (BTDC) as the engine increases in speed. In one application, a timing angle of 10 degrees after top dead center (ATDC) is selected for a engine idle speed of approximately 800 RPM. This relationship, which is controlled by the engine control unit, avoids stalling the engine when an operator suddenly decreases the engine speed.
U.S. Pat. No. 6,250,292 discloses a method which allows a pseudo throttle position sensor value to be calculated as a function of volumetric efficiency, pressure, volume, temperature, and the ideal gas constant in the event that a throttle position sensor fails. This is accomplished by first determining an air per cylinder (APC) value and then calculating the mass air flow into the engine as a function of the air per cylinder (APC) value. The mass air flow is then used, as a ratio of the maximum mass air flow at maximum power at sea level for the engine, to calculate a pseudo throttle position sensor value. That pseudo TPS (BARO) value is then used to select an air/fuel target ratio that allows the control system to calculate the fuel per cycle (FPC) for the engine.
U.S. Pat. No. 6,298,824 discloses a control system for a fuel injected engine including an engine control unit that receives signals from a throttle handle that is manually manipulated by an operator of a marine vessel. The engine control unit also measures engine speed and various other parameters, such as manifold absolute pressure, temperature, barometric pressure, and throttle position. The engine control unit controls the timing of fuel injectors and the injection system and also controls the position of a throttle plate. No direct connection is provided between a manually manipulated throttle handle and the throttle plate. All operating parameters are either calculated as a function of ambient conditions or determined by selecting parameters from matrices which allow the engine control unit to set the operating parameters as a function of engine speed and torque demand, as represented by the position of the throttle handle.
U.S. Pat. No. 6,757,606 discloses a method for controlling the operation of an internal combustion engine that includes the storing of two or more sets of operational relationships which are determined and preselected by calibrating the engine to achieve predetermined characteristics under predetermined operating conditions. The plurality of sets of operational relationships are then stored in a memory device of a microprocessor and later selected in response to a manually entered parameter. The chosen set of operational relationships is selected as a function of the selectable parameter entered by the operator of the marine vessel and the operation of the internal combustion engine is controlled according to that chosen set of operational parameters. This allows two identical internal combustion engines to be operated in different manners to suit the needs of particular applications of the two internal combustion engines.
U.S. Pat. No. 8,725,390 discloses systems and methods for optimizing fuel injection in an internal combustion engine that adjust start of fuel injection by calculating whether one of advancing or retarding start of fuel injection will provide a shortest path from a source angle to a destination angle. Based on the source angle and a given injection pulse width and angle increment, it is determined whether fuel injection will overlap with a specified engine event if start of fuel injection is moved in a direction of the shortest path. A control circuit increments start fuel injection in the direction of the shortest path if it is determined that fuel injection will not overlap with the specified engine event, or increments start fuel injection in a direction opposite that of the shortest path if it is determined that fuel injection will overlap with the specified engine event.
Unpublished U.S. patent application Ser. No. 15/597,749, filed May 17, 2017, discloses a method for controlling a marine internal combustion engine, which is carried out by a control module and includes: operating the engine according to a initial set of mapped parameter values configured to achieve a first fuel-air equivalence ratio in a combustion chamber of the engine; measuring current values of engine operating conditions; and comparing the engine operating conditions to predetermined lean-burn mode enablement criteria. In response to the engine operating conditions meeting the lean-burn enablement criteria, the method includes: (a) automatically retrieving a subsequent set of mapped parameter values configured to achieve a second, lesser fuel/air equivalence ratio and transitioning from operating the engine according to the initial set of mapped parameter values to operating the engine according to the subsequent set of mapped parameter values; or (b) presenting an operator-selectable option to undertake such a transition, and in response to selection of the option, commencing the transition.
Unpublished U.S. patent application Ser. No. 15/597,752, filed May 17, 2017, discloses a method for controlling a marine engine including operating the engine according to an initial set of mapped parameter values to achieve a first target fuel-air equivalence ratio, determining a first actual fuel-air equivalence ratio, and using a feedback controller to minimize a difference between the first target and actual ratios. Feedback controller outputs are used to populate an initial set of adapt values to adjust combustion parameter values from the initial set of mapped parameter values. The method includes transitioning to operating the engine according to a subsequent set of mapped parameter values to achieve a different target fuel-air equivalence ratio. The method includes determining a second actual fuel-air equivalence ratio, using the feedback controller to minimize a difference between the second target and actual ratios, and using feedback controller outputs to populate a subsequent set of adapt values to adjust combustion parameter values from the subsequent set of mapped parameter values.
Unpublished U.S. patent application Ser. No. 15/597,760, filed May 17, 2017, discloses a marine engine operating according to first and second sets of mapped parameter values to achieve a first fuel-air equivalence ratio and maintaining a stable output torque while transitioning to operating according to third and fourth sets of mapped parameter values to achieve a different fuel-air equivalence ratio. The first and third sets of mapped parameter values correspond to a first combustion parameter. The second and fourth sets correspond to a second combustion parameter. The transition includes: (a) transitioning from operation according to a current value of the first combustion parameter to operation according to a target value thereof; (b) transitioning from operation according to a current value of the second combustion parameter to operation according to a target value thereof; and (c) timing commencement or completion of step (b) and setting a rate of step (b) to counteract torque discontinuity that would otherwise result when performing step (a) alone.
Unpublished U.S. patent application Ser. No. 15/843,275, filed Dec. 15, 2017, discloses a method for controlling a marine internal combustion engine including operating the engine in a lean-burn mode, wherein a first fuel/air equivalence ratio of an air/fuel mixture in a combustion chamber of the engine is less than 1. The method includes comparing a change in operator demand to a delta demand deadband; comparing a speed of the engine to an engine speed deadband; and comparing a throttle position setpoint to a throttle position threshold. The method also includes immediately disabling the lean-burn mode in response to: (a) the change in operator demand being outside the delta demand deadband, and (b) at least one of: (i) the engine speed being outside the engine speed deadband, and (ii) the throttle position setpoint exceeding the throttle position threshold. The engine thereafter operates according to a set of mapped parameter values configured to achieve a second fuel/air equivalence ratio of at least 1.
The above-noted patents and patent applications are hereby incorporated by reference in their entireties.